000 AXNT20 KNHC 311047 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI JUL 31 2015 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N44W TO 20N46W MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH 700 MB TROUGHING BETWEEN 40W-50W AND LIES TO THE WEST OF A LOW-LEVEL MONSOONAL GYRE FOCUSED ON A 1009 MB LOW CENTERED ALONG THE MONSOON TROUGH NEAR 12N31W. NO SIGNIFICANT CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 09N76W TO 19N74W MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING BETWEEN 70W- 80W. ISOLATED MODERATE CONVECTION IS POSSIBLE FROM 12N-16N BETWEEN 74W-81W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 20N16W TO 16N20W TO A 1009 MB LOW NEAR 12N31W TO 08N48W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N48W TO 06N56W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 10N-16N BETWEEN 18W-26W. ISOLATED MODERATE CONVECTION IS FROM 07N-15N BETWEEN 28W-35W...AND FROM 05N-09N BETWEEN 36W-45W. ...DISCUSSION... GULF OF MEXICO... NORTHEASTERLY FLOW ALOFT PREVAILS OVER THE GULF THIS MORNING ON THE SOUTHEASTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER CENTRAL TEXAS. WHILE THE RIDGING IS THE MAIN SYNOPTIC FEATURE PROVIDING AN OVERALL DIFFLUENT ENVIRONMENT OVER THE GULF...AN UPPER LEVEL SHORTWAVE TROUGH AXIS REMAINS EMBEDDED WITHIN THE RIDGING EXTENDING FROM OFFSHORE OF THE DELMARVA REGION SW TO OVER CENTRAL ALABAMA. THE TROUGHING SUPPORTS A COLD FRONT EXTENDING FROM THE CENTRAL CAROLINAS SW TO SOUTHERN ALABAMA AND SW LOUISIANA. WEAK LOW-LEVEL MOISTURE CONVERGENCE ALONG AND MOSTLY SOUTH OF THE FRONT FOCUSED ALONG A SURFACE TROUGH EXTENDING FROM THE FLORIDA PANHANDLE TO 28N90W CONTINUES TO GENERATE SCATTERED SHOWERS AND TSTMS ACROSS PORTIONS OF THE CENTRAL GULF FROM 22N-29N BETWEEN 86W-94W. THE MAJORITY OF THIS ACTIVITY IS OCCURRING ON THE NORTHERN PERIPHERY OF A WEAK SURFACE RIDGE AXIS ANCHORED BY A PAIR OF 1018 MB HIGHS...ONE CENTERED IN THE WESTERN GULF NEAR 25N94W AND THE OTHER CENTERED ACROSS THE NW CARIBBEAN SEA NEAR 20N84W. THE WEAK AREA OF LOWER PRESSURE AND FRONTAL TROUGHING IS EXPECTED TO LINGER ACROSS THE NORTHERN GULF WATERS THROUGH SUNDAY NIGHT LATE AS IT FINALLY LIFTS NORTH OF THE COASTAL PLAIN BY MONDAY. SURFACING RIDGING IS EXPECTED TO RE-ESTABLISH ITSELF ACROSS THE GULF BASIN EARLY NEXT WEEK. CARIBBEAN SEA... MOST OF THE CARIBBEAN BASIN REMAINS FAIRLY TRANQUIL THIS MORNING WITH WATER VAPOR IMAGERY INDICATING RELATIVELY DRY CONDITIONS ALOFT FOCUSED ON VERY BROAD TROUGHING EXTENDING OVER THE NORTH- CENTRAL CARIBBEAN FROM AN UPPER LEVEL LOW NORTH OF HISPANIOLA NEAR 23N73W. THE TROUGHING EXTENDS WESTWARD INTO ANOTHER UPPER LEVEL LOW WITH SMALLER AREAL INFLUENCE CENTERED OVER THE GULF OF HONDURAS NEAR 17N85W. SHORTWAVE INFRARED SATELLITE IMAGERY INDICATES GENERALLY CLEAR SKIES WITH ONLY A FEW POSSIBLE ISOLATED SHOWERS AND TSTMS OCCURRING IN ASSOCIATION WITH A TROPICAL WAVE EXTENDING ALONG 76W. LOW-LEVEL MOISTURE AND CLOUDINESS EXTEND FARTHER EAST...WITH POSSIBLE ISOLATED SHOWERS OCCURRING E OF 67W. FINALLY...THE PRIMARY IMPACT FOR THE BASIN REMAINS FRESH TO STRONG BREEZE CONDITIONS GENERALLY S OF 16N BETWEEN 68W-79W. AS SURFACE RIDGING TO THE NORTH RE-ESTABLISHES HOLD ACROSS THE SW NORTH ATLC DURING THE WEEKEND...THESE TRADES ARE FORECAST TO GRADUALLY INCREASE SUNDAY INTO MONDAY ACROSS THE CENTRAL CARIBBEAN. ...HISPANIOLA... CURRENTLY...MOSTLY CLEAR SKIES AND FAIR CONDITIONS PREVAIL ACROSS THE ISLAND THIS MORNING. A FEW ISOLATED SHOWERS REMAIN EMBEDDED WITHIN THE TRADE WINDS TO THE EAST AND SOUTHEAST... HOWEVER NO SIGNIFICANT DEEP CONVECTION IS EXPECTED ACROSS THE ISLAND FRIDAY. ATLANTIC OCEAN... NORTHEASTERLY FLOW ALOFT PREVAILS OVER MUCH OF THE SW NORTH ATLC BETWEEN A BROAD UPPER LEVEL RIDGE COVERING MUCH OF THE SE AND SOUTH-CENTRAL CONUS AND AN ELONGATED UPPER LEVEL LOW CENTERED NORTH OF HISPANIOLA NEAR 23N73W. GLOBAL MODEL GUIDANCE INDICATES PLENTY OF MID-LEVEL ENERGY N OF 27N W OF 75W AND THIS ENERGY SUPPORTS A 1010 MB LOW CENTERED NEAR 33N76W AND ASSOCIATED SURFACE TROUGH EXTENDING SW TO 30N77W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING N OF 24N BETWEEN 74W-80W. THE REMAINDER OF THE SW NORTH ATLC BETWEEN 55W-75W REMAINS FAIRLY TRANQUIL UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED NEAR 28N60W. FINALLY...THE CENTRAL AND EASTERN ATLC IS ALSO UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH CENTERED S-SW OF THE AZORES NEAR 32N33W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN